The present disclosure relates to an electrophoretic device including a plurality of electrophoretic particles in an insulating liquid, to a method of manufacturing the same, and to a display unit.
In recent years, as mobile devices represented by mobile phones and personal digital assistants become widely used, display units (displays) having low power consumption and high image quality have been increasingly demanded. In particular, lately, in association with birth of delivery business of electronic books, personal digital assistants (electronic book terminals) for reading application having the purpose of reading textual information for a long time have attracted attention. Therefore, displays having display quality suitable for such an application have been desired.
As the display for reading application, for example, cholesteric liquid crystal displays, electrophoretic displays, electrochromic displays, twist ball displays, and the like have been proposed. In particular, reflective displays are preferable. One reason for this is that since the reflective displays perform bright display by utilizing reflection (scattering) of outside light as paper does, the reflective displays provide display quality close to that of paper. Further, in the reflective displays, a backlight is not necessitated, and therefore, power consumption is kept low.
A major candidate of the reflective displays is the electrophoretic display that generates contrast by utilizing an electrophoretic phenomenon, since power consumption is low and high-speed response is superior in the electrophoretic display. Therefore, various discussions have been made for display methods of the electrophoretic display.
Specifically, a method of dispersing two types of charged particles having different optical reflection characteristics in an insulating liquid, and moving the respective charged particles according to an electric field has been proposed (for example, see Japanese Examined Patent Application Publication No. S50-015115 and Japanese Patent No. 4188091). In this method, since the two types of charged particles have opposite polarities, a distribution state of the charged particles is changed according to the electric field.
Further, a method of arranging a porous layer in an insulating liquid and dispersing charged particles, and moving the charged particles through fine pores of the porous layer according to an electric field has been proposed (for example, see Japanese Unexamined Patent Application Publication No. 2005-107146, Japanese Examined Patent Application Publication No. S50-015120, Japanese Unexamined Patent Application Publication No. 2005-128143, and Japanese Unexamined Patent Application Publication No. 2002-244163). In this method, as the porous layer, a polymer film in which fine pores are formed by a boring process using a laser, a woven cloth made of synthesized fibers or the like, an open-cell porous polymer, or the like is used, for example.